OpenSSL Denial-of-Service Vulnerability (CVE-2020-1971) Threat Alert

OpenSSL Denial-of-Service Vulnerability (CVE-2020-1971) Threat Alert

January 5, 2021 | Mina Hao

Overview

On December 8, 2020, local time, OpenSSL released a security advisory disclosing a NULL pointer dereference vulnerability (CVE-2020-1971), rating the vulnerability as High-risk.

The vulnerability exists in the GENERAL_NAME_cmp function in OpenSSL. GENERAL_NAME_cmp compares different instances of a GENERAL_NAME to see if they are equal or not. When both GENERAL_NAMEs contain EDIPartyName, a NULL pointer dereference and a crash may occur, eventually causing a denial of service.

Therefore, if an attacker can control both items being compared, a crash might be triggered. For example, the attacker can trick a client or server into checking a malicious certificate against a malicious CRL.

Reference link:

https://www.openssl.org/news/secadv/20201208.txt

Affected Versions

  • OpenSSL 1.1.1
  • OpenSSL 1.0.2 (out of support)

Unaffected Version

  • OpenSSL 1.1.1i

Solution

OpenSSL has released new versions to fix the vulnerability. Affected users are advised to upgrade without delay.

The update is available at the following link:

https://www.openssl.org/source/

Statement

This advisory is only used to describe a potential risk. NSFOCUS does not provide any commitment or promise on this advisory. NSFOCUS and the author will not bear any liability for any direct and/or indirect consequences and losses caused by transmitting and/or using this advisory. NSFOCUS reserves all the rights to modify and interpret this advisory. Please include this statement paragraph when reproducing or transferring this advisory. Do not modify this advisory, add/delete any information to/from it, or use this advisory for commercial purposes without permission from NSFOCUS.

About NSFOCUS

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